96 PROCEEDINGS OF THE REGENTS. 



an account of the discoveries of Oersted, Arago, Davy, Ampere; of 

 the investigations hy Barlow and Sturgeon ; of his own researches, 

 commenced in 1828, and continued in 1829, 1830, and subsequently. 

 The details of his experiments and their results, though brief, are 

 very precise. There is abundant evidence to show that Professor 

 Henry's experiments and illustrations at Albany, and subsequently 

 at Princeton, proved, and were declared at the time by him to prove, 

 that the electric telegraph was now practicable ; that the electro- 

 magnet might be used to produce mechanical effects at a distance 

 adequate to making signals of various kinds, such as ringing bells, 

 which he practically illustrated. In proof of this, we quote a letter 

 to Professor Henry, from Professor James Hall, of Albany, late 

 president of the American Association for the Advancement of Science: 



January 19, 1856. 



Dear Sir: While a student of the Rensselaer School, in Troy, 

 New York, in August, 1832, I visited Albany with a friend, having 

 a letter of introduction to you from Professor Eaton. Our principal 

 object was to see your electro-magnetic apparatus, of which we had 

 heard much, and at the same time the library and collections of the 

 Albany Institute. 



You showed us your laboratory in a lower story or basement of 

 the buikling, and in a larger room in an upper story some electric 

 and galvanic apparatus, with various philosophical instruments. In 

 this room, and extending around the same, was a circuit of wire 

 stretched along the wall, and at one termination of this, in the recesi.'. 

 of a window, a bell was fixed, while the other extremity was con- 

 nected with a galvanic apj)aratus. 



You showed us the manner in which the bell could be made to ring 

 by a current of electricity, transmitted through this wire, and you 

 remarked that this method might be adopted for giving signals, by 

 the ringing of a bell at the distance of many miles from the point of 

 its connexion with the galvanic apparatus. 



All the circumstances attending this visit to Albany are fresh in ray 

 recollection, and during the past years, while so much has been said 

 respecting the invention of electric telegraphs, I have olten had occa- 

 sion to mention the exhibition of your electric telegraph in the Albany 

 Academy, in 1832. 



If at any time or under any circumstances this statement can be of 

 service to you in substantiating your claim to such a discovery at the 

 period named, you are at liberty to use it in any manner you jdease, 

 and I shall be ready at all times to repeat and sustain what I have 

 here stated, with many other attendant circumstances, should they 

 prove of any importance. 



I remain very sincerely and respectfully yours, 



JAMES HALL. 



Professor Joseph Henry. 



